Heterodera ustinovi (grass cyst nematode).
Abstract There is limited evidence available to suggest that H. ustinovi is invasive. The identical COI halpotypes shared between the USA and Europe most likely represent recent introductions. The small amount of genetic information from North America suggests that H. ustinovi is widespread in the south west (Arizona), midwest (Ohio) and New England states, with little genetic differentiation. H. ustinovi has not been found on any plant species in the USA other than introduced Agrostis species and in turf/golf course settings. A lot of nematodes are transported in turf from turf farms. The initial discovery on native Agrostis in the Ukraine would suggest a potential native parasite existing on a native plant species, but, there are very few of samples on which to base these comparisons.